From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#46933: Possible bugs in filepos-to-bufferpos / bufferpos-to-filepos Date: Sun, 28 Mar 2021 17:51:35 +0300 Message-ID: <83tuovmivc.fsf@gnu.org> References: <87y2e7s65m.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="6875"; mail-complaints-to="usenet@ciao.gmane.io" Cc: gregory@heytings.org, 46933@debbugs.gnu.org To: handa Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun Mar 28 16:52:12 2021 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lQWlv-0001g1-NN for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 28 Mar 2021 16:52:11 +0200 Original-Received: from localhost ([::1]:34712 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lQWlu-00028o-1R for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 28 Mar 2021 10:52:10 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:36118) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lQWlm-00026d-Ft for bug-gnu-emacs@gnu.org; Sun, 28 Mar 2021 10:52:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:35198) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lQWlm-00046a-6O for bug-gnu-emacs@gnu.org; Sun, 28 Mar 2021 10:52:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1lQWlm-0004pZ-4S for bug-gnu-emacs@gnu.org; Sun, 28 Mar 2021 10:52:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 28 Mar 2021 14:52:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 46933 X-GNU-PR-Package: emacs Original-Received: via spool by 46933-submit@debbugs.gnu.org id=B46933.161694309718536 (code B ref 46933); Sun, 28 Mar 2021 14:52:02 +0000 Original-Received: (at 46933) by debbugs.gnu.org; 28 Mar 2021 14:51:37 +0000 Original-Received: from localhost ([127.0.0.1]:46744 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lQWlN-0004ou-G8 for submit@debbugs.gnu.org; Sun, 28 Mar 2021 10:51:37 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:43052) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lQWlL-0004oh-HF for 46933@debbugs.gnu.org; Sun, 28 Mar 2021 10:51:35 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:53205) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lQWlF-0003rf-Ok; Sun, 28 Mar 2021 10:51:29 -0400 Original-Received: from 84.94.185.95.cable.012.net.il ([84.94.185.95]:3176 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1lQWlF-0004DP-7A; Sun, 28 Mar 2021 10:51:29 -0400 In-Reply-To: <87y2e7s65m.fsf@gnu.org> (message from handa on Sun, 28 Mar 2021 23:29:41 +0900) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:203173 Archived-At: > From: handa > Cc: gregory@heytings.org, 46933@debbugs.gnu.org > Date: Sun, 28 Mar 2021 23:29:41 +0900 > > > In any case, the problem is not with encoding, the problem is with > > decoding. Encoding doesn't have this problem because we always encode > > more than enough (we use the value of BYTE as the count of > > _characters_ to encode, so for ISO-2022 encoding it is usually much > > more than needed). By contrast, when decoding, we decode exactly > > BYTE+1 bytes, which then hits the problem if that offset is inside a > > shift sequence. > > Then, that implementation should be changed. > > Any coding system can have :post-read-conversion and > :pre-write-conversion functions, it is not guaranteed that encoded byte > length is greater than the number of characters. Agreed, but AFAICT, ISO-2022-JP doesn't have any of these attributes, right?